Heat levels vary in different lights. To avoid damage and distortion of filters, do NOT use filter lens caps on lights continuously.

Lens uses:

Ruby: preserves night vision

Amber: cuts through smoke

Emerald: for low-light conditions

Sapphire: for tracing blood trails

Clear: improves light beam focus

Keep a set of these with every 42mm flashlight. In the car, you can use the ruby one to view maps at night without compromising your night vision. The sapphire color is great for tracking game that runs after being shot. The uses are endless!